In fact, as the Minnesota House Committee on Public Safety and Security Policy will hear in testimony today, Stand Your Ground laws do not allow the initiation of force. Since the response must be proportionate to the threat, a defendant cannot shoot unless he is in imminent danger of serious bodily harm or death. Or, at least, a reasonable person must have cause to perceive such a grave threat.

Prior to Stand Your Ground, citizens have had to retreat as far as possible and then warn the criminal of their intention to shoot. The concept of “appropriate retreat” is vague and potentially confusing to a defendant who needs to take immediate, decisive action. Delay can sometimes be fatal. Overzealous prosecutors have sometimes argued that the defendant should have retreated even farther. These trials, even if they end in acquittal, are very costly and destroy defendants’ lives.

It stands to reason that the most likely victims of violent crime will benefit the most from Stand Your Ground laws. And who are the most likely victims? Poor blacks in high-crime, urban areas who definitely cannot count on the police to come to their rescue in time.

Thirty-three states have laws that remove the requirement to retreat. Some states have had these laws since their founding. Support for them had been overwhelmingly bipartisan until the last few years. In 2004, even state Sen. Barack Obama co-sponsored and voted for a bill expanding Illinois’ Stand Your Ground law.

Florida has the most detailed and by far the most accurate data on Stand Your Ground Laws, compiled by the Tampa Bay Times. Blacks make up 16.7 percent of Florida’s population, but they account for 34 percent of defendants who invoke this defense. Black defendants who invoke this statute are acquitted 4 percentage points more frequently than whites who do so.

The Times collected all 119 cases in which people charged with murder relied on Stand Your Ground, from the first cases in 2006 to Oct. 1, 2014. Those claiming racism point out: While 67 percent of those who killed a black person faced no penalty, that is true of only 57 percent of those who killed a white person.

But this misses the fact that blacks are overwhelmingly killed by other blacks. In most cases, people acquitted of killing a black person in self-defense were black themselves. About 64 percent of blacks raising the Stand Your Ground defense were acquitted, compared with 60 percent of whites.

So does that mean that white defendants are discriminated against? That isn’t true, either.

The data also show that compared with whites, blacks killed in these cases were 26 percentage points more likely to be armed with a gun and 25 percentage points more likely to be committing a crime. These data suggest that many black attackers did pose a mortal threat.

In 2012, Minnesota Gov. Mark Dayton vetoed a Stand Your Ground bill because he claimed that it would endanger the lives of police officers. But officers are protected in two ways in both that earlier bill and this one. To use justifiable, deadly force against anyone, a “reasonable” person must believe that someone is about to commit a serious violent crime against him or her. In addition, if you know that the person is a police officer, under no circumstances are you allowed to use deadly force against an officer who is acting lawfully.

My research looked at all states that have enacted Stand Your Ground between 1977 and 2012, either through legislation or through court decisions. I consistently found subsequent drops in murder, rape, robbery and aggravated assault rates. On average, murder rates fell by about 1.5 percent annually during the first 10 years that the law was in effect.

Restricting self-defense harms the most vulnerable members of society. It compromises the safety of poor blacks who live in high-crime, urban areas. It also endangers physically weaker individuals. As police know all too well, they simply can’t be there all the time to save people. We ought to have laws that show more compassion for the plight of people in these harrowing situations.

John R. Lott Jr. is the president of the Crime Prevention Research Center. He will be testifying before the Minnesota House Committee on Public Safety and Security Policy on the Stand Your Ground bill.